Many factors can influence a teacher's self-efficacy beliefs, including the support of his or her administrators--the principal and assistant principal. This interpretive phenomenological study sought to describe the influence that administrator support had on teacher self-efficacy. The conceptual framework of this study was Bandura's (1986) social cognitive theory with a specific focus on the construct of self-efficacy (Bandura, 1977a). The research questions addressed the impact of a supportive administrator and sought to describe specific examples of administrator practices that influenced individual teacher self-efficacy. Data were collected through in-depth interviews with teachers in a school district in the southeastern United States. Participants were selected for interviews based on their experiences in education with multiple administrators. All interviews were taped, transcribed, and analyzed using coding and thematic analysis. The study provided detailed descriptions of how administrative support influenced teacher self-efficacy and examples of supportive administrative practices. Six supportive administrator practices were identified: communication, monitoring and evaluating instruction, providing contingent rewards and recognition, situational awareness, consideration, and consistency. Supportive administrator practice influenced teacher self-efficacy through five themes: increasing confidence, motivation, feeling valued, reinforcement, and leaving or staying in a school or the profession. This study could contribute to positive change in administrator/teacher relationships and help administrators increase teacher self-efficacy, thereby leading to increased quality of instruction, focus on academics, positive learning environments, and student achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]